It has heretofore been proposed to provide a flexible wiper blade for vehicle windshields with a pressure distributing frame formed of multiple yokes of spring leaf material so that the blade will conform to the configuration of a curved windshield. It has also been proposed to provide a weather proof bonnet, or hood, enclosing the pressure distributing frame to protect it from ice, sleet, and snow during non use, as illustrated in U.S. Pat. Nos. 2,727,271 of Dec. 20, 1955 and 2,728,100 of Dec. 27, 1955 to Oishei.
Such bonneted wiper blades are commercially available as "Winter Wiper Blades", Stock Nk. ARL-18-2, W. B. 618 from Trico Products Corporation, Buffalo, New York 14203.
It has further been proposed to provide such a bonneted wiper blade with a single, flat strip-like electrical conductor extending along the base edge of the flexible wiper blade to provide heat for the distributing frame within the bonnet, as in U.S. Pat. No. 3,619,556 to Deibel of Nov. 9, 1971.